A good installation starts before haul-out.

Agree the specification first

Before booking the work, confirm the seal family, shaft size, stern-tube fit and available room. Give the installer the selected part number and the corresponding drawing. Include any plumbing accessories in the discussion.

A replacement of the same nominal size still deserves an inspection of the surrounding installation. The condition of the shaft, coupling and attachment area belongs in that assessment.

Use the manual for the actual model

Type A, PRO and Type B are not identical installation procedures. Bellows construction, rotor retention and compression requirements vary. Use the supplied instructions for the exact product and keep them with the vessel records.

The initial contact position and the working compressed position are different. The installer establishes the specified setup using the model’s procedure rather than simply copying the position of the previous seal.

Resolve the water arrangement

Cooling and lubrication water must reach the sealing faces. Current PSS guidance allows a vent for qualifying low-speed installations, while high-speed boats and certain shaft-log arrangements require a positive feed. A yacht label alone does not decide the answer.

Discuss vessel speed, shaft-log bearings and twin-engine operation with the installer. Water supply routing is part of the installation design, and it should be checked against current instructions rather than an older brochure.

Protect the sealing components

The prepared shaft, carbon face and rotor face need careful handling. The manual specifies suitable installation lubricants and warns against using oil, grease or silicone. Cup-point set screws must not be reused after their tips have been compressed against the shaft.

Have the required replacement parts and tools ready before dismantling. This is particularly useful when the job combines seal replacement with other driveline work.

Make commissioning part of the job

Before the boat returns to ordinary use, the completed installation needs the manufacturer’s launch and operational checks. Record the fitted part number, installation date and any work on the water feed.

Ask the installer to show you the inspection points and identify the correct service interval. A clear handover gives you a useful reference for future maintenance and makes a later parts enquiry much simpler.

• Confirm the product and drawing.
• Plan water feed or venting.
• Follow the model-specific manual.
• Complete and record commissioning.